Companies do not care about their employees. They hire employees to make money. That's it. Nothing else.
As a percentage, there isn't that many H1-Bs working for a particular company. I think Dell has about 2000 people depending on where you look. Dell doesn't publish these numbers. What you need to be worried about is, as they get rid of people in the US, they move the jobs to other countries with cheaper rates. That is what you need to follow.